show: don't obligate to have the colon on fields

src/client/opamListCommand.ml

@@ -432,24 +432,19 @@ let field_names = [
 ]
 
 let string_of_field = function
-  | Field s -> s^":"
+  | Field s -> s
   | f -> List.assoc f field_names
 
 let field_of_string =
   let names_fields = List.map (fun (a,b) -> b, a) field_names in
+  let opam_fields = List.map fst OpamFile.OPAM.fields in
   fun s ->
-    if OpamStd.String.ends_with ~suffix:":" s then
-      Field (OpamStd.String.remove_suffix ~suffix:":" s)
-    else
-    try List.assoc s names_fields
-    with Not_found ->
-      OpamConsole.error_and_exit `Bad_arguments
-        "No printer for %S%s" s
-        (if not (OpamStd.String.ends_with ~suffix:":" s) &&
-            List.mem_assoc s (OpamFile.OPAM.fields)
-         then Printf.sprintf ". Did you mean the opam field \"%s:\" \
-                              (with a colon)?" s
-         else "")
+    match List.find_opt (fun x -> s = x || s = x^":") opam_fields with
+    | Some field -> Field field
+    | None ->
+      try List.assoc s names_fields
+      with Not_found ->
+        OpamConsole.error_and_exit `Bad_arguments "No printer for %S" s
 
 let version_color st nv =
   let installed = (* (in any switch) *)